Question
A student observes that when a solution of nitric acid is mixed with a solution of sodium carbonate in a beaker, bubbles form and the beaker feels warm. Which of the following statements best describes this reaction?

A.
The reaction between an acid and a base forms a precipitate.
B.
Gas formation is evidence of a chemical reaction.
C.
The molecular arrangement of the reactants does not change after the reaction.
D.
The reaction between nitric acid and sodium carbonate is endothermic by nature.

A.
The reaction between an acid and a base forms a precipitate.
B.
Gas formation is evidence of a chemical reaction.
C.
The molecular arrangement of the reactants does not change after the reaction.
D.
The reaction between nitric acid and sodium carbonate is endothermic by nature.
Answers
GPT-4o mini
The best statement that describes the reaction between nitric acid and sodium carbonate is:
**B. Gas formation is evidence of a chemical reaction.**
This is correct because the bubbles observed during the reaction indicate the formation of carbon dioxide gas (CO₂), which is a byproduct of the reaction between an acid (nitric acid) and a carbonate (sodium carbonate). Additionally, the beaker feeling warm suggests that the reaction is exothermic (not endothermic), which further supports that gas formation is a sign of a chemical change occurring.
The other options are not accurate:
- A is incorrect as there is no precipitate formed in this reaction; the reaction produces gas and dissolved products.
- C is incorrect because the molecular arrangement of the reactants does indeed change during the reaction.
- D is incorrect since the warmth indicates that the reaction is exothermic, not endothermic.
**B. Gas formation is evidence of a chemical reaction.**
This is correct because the bubbles observed during the reaction indicate the formation of carbon dioxide gas (CO₂), which is a byproduct of the reaction between an acid (nitric acid) and a carbonate (sodium carbonate). Additionally, the beaker feeling warm suggests that the reaction is exothermic (not endothermic), which further supports that gas formation is a sign of a chemical change occurring.
The other options are not accurate:
- A is incorrect as there is no precipitate formed in this reaction; the reaction produces gas and dissolved products.
- C is incorrect because the molecular arrangement of the reactants does indeed change during the reaction.
- D is incorrect since the warmth indicates that the reaction is exothermic, not endothermic.